A jail unit designed to hold disruptive inmates has been criticised for holding mentally ill prisoners, following incidents of self-harm.

Woodhill prison in Milton Keynes was one of three units set up by the Labour government in 1998 to hold the most dangerous and disruptive inmates, but not those with mental health issues. Yet the unit's operational manager has confirmed in a letter seen by the Guardian that incidence of self-harm is high and it is holding prisoners who have mental health problems.